The present invention relates to an electronic taximeter for computing a fare in accordance with a selectable tariff, and more particularly to such an electronic taximeter which includes a display for continually displaying the fare as it accrues, and for displaying a tariff at which the fare is being computed.
Electronic taximeters are known. The known electronic taximeters generally include a transducer coactive with a wheel or a transmission of a taxi for developing pulses at a rate determined by the speed of the taxi. These pulses are received by fare computing circuitry which calculates a fare in accordance with a selected tariff and the number of pulses received from the transducer during a trip.
The known electronic taximeters also include displays for displaying a fare. The fare display is generally located near a taxi driver to enable him to easily read it, and this necessitates a passenger in a back seat of the taxi having to shift around in order to get a good look at the fare display. It would be desirable to provide a duplicate display at the back seat of a taxi, or positioned somewhere closer to passengers in the back seat so that they can conveniently determine the fare themselves by inspection of the fare display.
The problems arising from trying to provide a duplicate fare display are substantial. These fare displays generally include a plurality of display elements which display numerals and which are each driven by a plurality of different signals which determine the particular numerals indicated by the display elements. A display element commonly employed is comprised of an array of seven segments which may be individually illuminated or which may be illuminated in different combinations in order to define different luminous numerals. Each of these display elements requires seven different input leads for receiving seven different input signals to drive different ones of the segments. Thus, if the fare display is comprised of five display elements, a total of at least thirty five different leads is required to drive the fare display. If a duplicate display is provided remote from the electronic taximeter normally positioned near the driver, then at least thirty five leads are required to connect the duplicate display with the electronic taximeter, exclusive of power leads, control signal leads, etc. Moreover, if the display and duplicate display also indicate tariff as well as accrued fare, even more connecting leads are required.
The connecting leads between a duplicate display and an electronic taximeter normally include a connector to permit disconnection of the duplicate display in order to allow it to be easily installed and removed for repair. This connector is a source of considerable problems. Taxicabs are high vibration environments and electrical connectors subjected to the vibrations become intermittent. Even high quality connectors are not completely immune from vibration caused intermittance, and the repair or replacement of these connectors is time consuming and costly. Moreover, it is irritating to passengers when the duplicate display malfunctions and displays incorrect fares, and this is a source of ill will towards the taxicab driver and company.